Meryl Streep (pictured), Mike Nichols, Yo-Yo Ma and Eva Longoria discover they are distant cousins in PBS’ “Faces of America” with Henry Louis Gates Jr. The four-part documentary airing in February uses DNA to explore the genealogy of 12 famous Americans. To promote it, journalists are getting their cheeks swabbed to find out if they’re related to celebrities or to each other. “All information will be confidential and given to you in a sealed envelope at the premiere,” the promoter said, adding, “We ask that you allow us to reveal your distant cousins live that night.”